Analyzing Antioxidant Properties of Caulerpa racemosa Harvested in Jepara Using ABTS and β-Carotene Bleaching Methods

Ariyanti Ariyanti (Doctoral Program in Pharmacy, Faculty of Pharmacy, Universitas Gadjah Mada, Sleman, Special Region of Yogyakarta Faculty of Health, Pharmacy Study Program of Pharmaceutical Sciences, Ngudi Waluyo University Ungaran, Semarang, Central Java)
Akhmad Kharis Nugroho (Department of Pharmaceutical Sciences, Faculty of Pharmacy, Universitas Gadjah Mada, Sleman, Special Region of Yogyakarta)
Triana Hertiani (Department of Pharmaceutical Biology, Faculty of Pharmacy, Universitas Gadjah Mada, Sleman, Special Region of Yogyakarta)
Adhyatmika Adhyatmika (Department of Pharmaceutical Sciences, Faculty of Pharmacy, Universitas Gadjah Mada, Sleman, Special Region of Yogyakarta)
Eka Noviana (Department of Bioanalytical Chemistry, Faculty of Pharmacy, Universitas Gadjah Mada, Sleman, Special Region of Yogyakarta)

Majalah Obat Tradisional
Vol 31, No 2 (2026)

Caulerpa racemosa (Forsskal) J. Agardh, commonly known as sea grapes, is a green macroalga traditionally consumed as food. While previous studies have examined the antioxidant activity and chemical constituents of C. racemosa from various coastal regions, the species from Jepara, Indonesia, an ecologically distinct marine area, remains largely underexplored. This study aims to evaluate the antioxidant activity of C. racemosa ethanol extract using ABTS and β-carotene bleaching (BCB) assays, characterize its chemical profile through thin-layer chromatography (TLC) and Fourier-transform infrared (FT-IR) spectroscopy, and quantify the caulerpin content via high-performance liquid chromatography (HPLC). Extraction was performed with 96% ethanol, and phytochemical screening on TLC employed spray reagents: Dragendorff’s for alkaloids, anisaldehyde for terpenoids/steroids, and FeCl₃ for phenolics and flavonoids. The phytochemical characterization confirmed the presence of alkaloid compounds. The extract exhibited moderate antioxidant activity, with IC₅₀ values of 57.05 ppm (ABTS) and 63.75 ppm (BCB), compared to quercetin (11.87 ppm, ABTS) and BHT (26.35 ppm, BCB). Caulerpin content in the 1000 ppm extract was 26.86 ppm. These findings indicate that C. racemosa from Jepara is a promising source of natural antioxidant compounds with potential pharmaceutical applications and warrants further investigation.